Coupler for respiratory apparatus



FIG. 1 is an isometric view of a side and the upper end of my new coupler for respiratory apparatus;

FIG. 2 is an isometric view thereof, showing the other side and lower end thereof;

FIG. 3 is a view in side elevation thereof, with a portion of the wall broken away and an interior stem portion shown in central cross-section;

FIG. 4 is a view in front elevation of the device;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a top plan view thereof. 

The ornamental design for a coupler for respiratory apparatus, substantially as shown and designed. 